Purke, 23, will have the procedure performed by Dr. James Andrews, the Nationals announced on Wednesday afternoon. He was the team's third-round pick in the 2011 Draft and received a $4 million Major League contract out of TCU.

The Texas native, who is on Washington's 40-man roster, has suffered through a rough start to his third Minor League season. In eight starts, the left-hander was 1-6 with an 8.04 ERA with 22 strikeouts over 31 1/3 innings for Double-A Harrisburg.

Purke was placed on the Senators' seven-day disabled list May 20 after allowing four runs on eight hits over four frames in his sixth loss, this one to New Britain on May 18. The Nationals said they were "gathering information and assessing" Purke, according to the Washington Post. He traveled to Washington to seek a second opinion on his elbow May 21, assistant general manager Doug Harris told the paper.

His only successful outing this year came May 7, when he limited Richmond to a pair of hits over six innings for the win. The 6-foot-4 southpaw dropped his first five starts, allowing four or more runs in each outing. He's walked 18 batters and hitters own a .331 average against him this year.

This won't be the first surgery for Purke. In 2012, he underwent shoulder debridement surgery that helped remove damaged tissue and debris from his left arm. He appeared in just three games that season, striking out 14 in 15 1/3 frames for Class A Hagerstown. He appeared in 18 starts for the Suns and Class A Advanced Potomac last year, finishing 6-4 with a 3.80 ERA in 90 innings.